SC6 is in a quite stable state. It has not been getting updates since… well, since ages. And none are planned for the future (dear Bandai Namco, we don’t need them, we are waiting for SC7). It’s basically a close-to-perfect condition for creating a pro tier list. A player has a lot of time to experience different characters and place them according to their true power.
Bluegod did that recently and posted a SC6 tier list on Twitter. Even if we don’t see the guy at tournaments too much now, being 2nd at Soulcalibur World Invitational 2019 and winning SC6 Evo Japan 2020 — it’s quite a statement.